Dumbbell



FIG. 1 is a perspective view of a first embodiment of a dumbbell;

FIG. 2 is a side view of the dumbbell of FIG. 1;

FIG. 3 is a front view of the dumbbell of FIG. 1;

FIG. 4 is a perspective view of a second embodiment of a dumbbell;

FIG. 5 is a side view of the dumbbell of FIG. 4;

FIG. 6 is a front view of the dumbbell of FIG. 4;

FIG. 7 is a perspective view of a third embodiment of a dumbbell;

FIG. 8 is a side view of the dumbbell of FIG. 7; and,

FIG. 9 is a front view of the dumbbell of FIG. 7.

The broken lines illustrate portions of the article that form no part of the claimed design. 

CLAIM The ornamental design for a dumbbell, as shown and described. 